Lord Cardigan appeared before Chippenham magistrates this morning charged with harassment without violence but the hearing was adjourned because the bench had to be disqualified.
Lord Cardigan, 61, of Savernake Lodge in the Savernake Estate, who appeared under the name David Michael James Brudenell-Bruce, pleaded not guilty to the charge.
He is accused of making a total of approximately 69 unwanted calls to John Moore, a trustee of the estate, on April 5 and 12 last year.
Mr Moore became a trustee in November 2008 and said before his appointment he had a good relationship with Lord Cardigan.
However, the relationship became strained when Lord Cardigan took a dislike to the way the estate was being run.
Mr Moore, who is a senior clerk at the chambers of John Gardener QC, was at work when he received the calls.
It ais alleged that, on April 5, Lord Cardigan made about 39 phone calls to the chamber, the first was made at around 2pm.
Previously Lord Cardigan had asked both Mr Moore and fellow trustee Wilson Cotton to send a plumber to Savernake Lodge.
Mr Moore told the court that a number of plumbers had been asked to go up to the lodge but they had refused.
"He said 'plumber' and then put the phone down," Mr Moore said.
"There were further phone calls in which he said 'plumber' sometimes and other times he would say nothing, he just put the phone down.
"I said words to the effect 'this is harassment, I'm calling the police if this continues and he said words to the effect 'you are welcome to'."
Before Mr Moore was cross-examined by the defence he was asked to leave the court while evidence was discussed.
During this period the prosecutor, Michael Little, was accused of saying something which was in breech of court guidelines.
It was requested that the bench be dismissed in light of this accusation.
Paul Gane, chairman of the bench, said: "We feel that a fair-minded person could perceive bias so therefore this needs to be relisted for a two-day trial."
Lord Cardigan is due to appear at North West Wiltshire Magistrates' Court, Chippenham, next Monday when a new trial date will be set.